a. Field of the Invention
The disclosure relates to electrophotographic imaging devices, and in particular, devices and methods for manufacturing or remanufacturing toner printer cartridges.
b. Background Art
Printer cartridges, such as toner printer cartridges, are used in various electrophotographic imaging devices, such as laser printers, copiers, facsimile machines, and multifunction imaging devices. Once original equipment manufacturer (OEM) toner printer cartridges are used, they are often recycled and remanufactured. The process of remanufacturing a toner printer cartridge may include cleaning the cartridge, repairing damaged parts, replacing worn parts, reassembling with new parts, and replenishing the cartridge with toner. The process of remanufacturing a toner printer cartridge requires that the toner printer cartridge be disassembled so that access to the various component parts may be achieved, and further requires that the toner printer cartridge be reassembled for subsequent use.
The component parts of toner printer cartridges typically include a doctor blade or doctor bar, a toner hopper, a waste hopper, a wiper blade, a primary charge roller (PCR), a developer roller, and an organic photoconductive (OPC) drum. The term “doctor blade” is a commonly used term in the toner printer cartridge manufacturing and remanufacturing industries and refers to an elongated material that usually includes an elongated holder or rod with an elongated blade attached to the elongated holder or rod. The elongated holder or rod is usually made of metal, and the elongated blade may be made of plastic or metal. The elongated blade may be positioned at an angle from the elongated holder or rod and may be positioned proximate to the developer roller with a predetermined distance.
When the toner printer cartridge is in operation, the doctor blade or doctor blade assembly is typically stationary while the developer roller rolls next to the doctor blade. The doctor blade or doctor blade assembly ensures that the right amount of toner sticks to the developer roller. However, not all toner may be absorbed by the developer roller. The toner that is not absorbed by the developer roller typically accumulates around the developer roller. Since the doctor blade and the developer roller are separated by a relatively small predetermined space, the blade controls the thickness of the toner that adheres to the developer roller by scraping off toner that is not absorbed by the developer roller. If there is an excess amount of toner on the developer roller, the doctor blade scrapes off the excess amount. The developer roller then transfers the toner to the OPC drum. The OPC drum that is coated with toner then rolls over a sheet of paper, which is usually given a negative charge by the PCR. The charge of the paper is typically less negative than the charge of the toner, and thus the paper attracts the toner. The toner may be embedded on the paper according to the print pattern.
The doctor blade or doctor blade assembly and the developer roller are usually detached from the toner printer cartridge during the remanufacturing process for cleaning. After cleaning, the doctor blade or doctor blade assembly and the developer roller may be reassembled together usually manually with a screw driver. An assembler or user may align or position the doctor blade above the developer roller. The assembler or user may press on one side of the doctor blade or doctor blade assembly and then attach with fastener or attachment means, such as screws, the same side of the doctor blade to the toner printer cartridge. The assembler or user may then execute the same steps on the remaining side. Aligning and positioning the doctor blade or doctor blade assembly during replacement and remanufacture may require that the doctor blade or doctor blade assembly be aligned or positioned within a tenth of millimeters of an acceptable alignment or position point to maximize print quality during printing. Many known OEM toner printer cartridges are designed to have a doctor blade or doctor blade assembly that may have the capability of being adjustable in order to adjust the doctor blade position. Thus, it may be difficult for the remanufacturer to manually align the doctor blade or doctor blade assembly to the correct position.
Known methods of assembly, manufacture, or remanufacture of toner printer cartridges may not provide a uniform distance between the doctor blade or doctor blade assembly and the developer roller from one side of the doctor blade to the other. As a result, the print quality may be affected, as the toner level on the developer roller is not effectively regulated by the doctor blade. One side of the developer roller may produce darker images than the other, or vice-versa. Moreover, known methods of assembly, manufacture, or remanufacture of toner printer cartridges, such as positioning or aligning a doctor blade or doctor blade assembly, may require an assembler or user to manually align and position the doctor blade or doctor blade assembly and may result in misalignment or damage to the doctor blade or doctor blade assembly. For example, an assembler or user may have to manually hold the doctor blade or doctor blade assembly in order to tighten fasteners such as screws to secure the doctor blade or doctor blade assembly to the toner hopper.
In addition, known methods of assembly or remanufacture of toner printer cartridges may require permanent attachment of two or more spacers, inserts, shims, or other spacing elements within the gap or area formed between the doctor blade or doctor blade assembly and the printer cartridge body in order to maintain a desired gap or area distance. The use of such permanent spacers, inserts, shims, or other spacing elements may increase the overall cost and complexity and decrease the overall efficiency of the assembly, manufacturing, or remanufacturing processes. Moreover, such spacers, inserts, shims, or spacing elements may have to have a required thickness that may limit the type of spacer, insert, shim, or spacing element that may be used.
In addition, known methods of assembly or remanufacture of toner printer cartridges may require the use of fixture elements to hold the doctor blade or doctor blade assembly and/or toner hopper and/or toner printer cartridge in place while positioning and aligning the doctor blade or doctor blade assembly. The use of such fixture elements may increase the overall cost and complexity and decrease the overall efficiency of the assembly, manufacturing, or remanufacturing processes.
Accordingly, there is a need for an improved doctor blade assembly and method for aligning doctor blade assemblies in toner hoppers of toner printer cartridges, that overcomes the issues associated with known devices and methods.